In my view, the tenant is paying the property taxes on the space they rent to live in, so the mutual fund investor (who is also a tenant) is paying property taxes, just on their housing not on the funds.
It's rolled into the rent, but there's no reason to me to think that the landlord is paying it when the tenant is the one bringing the money into the system.
So you have checked with every property owner and verified this?
I actually rent now, from my father (because he makes bad real estate decision despite having his real estate license). After talking with my landlord, who I know well and often talk to, I learned that in this area there are laws about how low rents can be. In his specific situation he is not allowed to rent the property for less than 125% of the price of his mortgage payment which must include the property taxes. Apparently, this is to insure there is money repairs.
So as for houses in Omaha I am fairly certain you are factually in error. I suspect other jurisdictions have other things going on in general, but it seems reasonable that most people do simple things like take their expenses into account which includes tax.
In contrast, the capital gains from owning a home are exempt for a certain amount, and "imputed rent" (the savings from not having to rent a similar house at current rates) is untaxed, like any other cost-saving purchase. [1]
(One small advantage the other way is that you don't have to pay "property taxes" on mutual funds, though you do have to pay management fees, which, even for index funds, are of similar magnitude.)
[1] IIRC the original income tax did cover imputed rents of sufficient magnitude.